I feel like the concern being raised here is not that the game won't complete, but rather that the game has a LOT of ways it still needs to improve, and many of them are ways that go against Larian's original ideology.. and so for those improvements to actually happen, they need that volume of data and feedback from a large pool of independent testers. Without it, the game will complete and launch anyway, but some folks are worried that it will remain as intrinsically dissatisfying and underwhelming as many are currently finding it due to the problems it has - and folks want the game to be as good as it could be.